Is the mysql server on same machine. If not then you will need to point it to the right server and use port 3306 if my memory serves me right.

So there could be a few issues. However, I run Abyss 2.7, mysql 5.5.23, php 5.3.10 and latest version of phpmyadmin. All on same machine with no issues. Generally you can log into it with no extra steps needed.